In semiconductor manufacturing processes, miniaturization of circuit patterns formed on semiconductor substrates (wafers) has been rapidly advancing, and the importance of process monitoring that monitors, for example, whether the patterns are formed following designs or not has been increasing more and more. For example, in order to detect occurrence of troubles and flaws (defects) in the semiconductor manufacturing processes in an early stage or in advance, measuring and inspecting of, for example, circuit patterns on the wafers are carried out at the end of each manufacturing step.
In the above-described measuring/inspecting, in a measuring/inspecting apparatus such as an electron microscope apparatus (SEM) using a scanning electron beam system and in a measuring/inspecting method corresponding thereto, a target wafer (sample) is irradiated with an electron beam (electron ray) while carrying out scanning, and the energy of secondary electrons, etc. generated as a result thereof is detected. Then, based on the detection, an image(s) (measurement image or inspection image) is generated, for example, by signal-processing/image-processing, and measuring and inspecting are carried out based on the image.
For example, in the case of an apparatus (inspecting apparatus, inspecting function) which carries out inspecting of defects in a circuit pattern, images of similar circuit patterns are mutually compared by using the inspection image, and the part at which a difference therebetween is large is determined/detected as a defect. In the case of an apparatus (measuring apparatus, measuring function) which carries out measuring of the circuit pattern, the amount of generation of the secondary electrons, etc. is varied depending on the irregularities (surface profile) of the sample; therefore, variations, etc. in the surface shape of the sample can be captured by an evaluation process of the signals of the secondary electrons. Particularly, when the fact that the signals of secondary electrons are rapidly increased/decreased at an edge part of a circuit pattern is utilized to estimate the position of the edge in the image of the circuit pattern, the dimensional values, etc. of the circuit pattern can be measured. Based on the measurement result thereof, for example whether the processing of the circuit pattern is good or not can be evaluated.
Known technique examples related to the above-described measuring/inspecting include: Japanese Patent Application Laid-Open No. 2006-093251 (Patent Document 1), Japanese Patent Application Laid-Open No. H7-326314 (Patent Document 2), Japanese Patent Application Laid-Open No. 2006-013388 (Patent Document 3), etc.
Patent Document 1 describes, for example, a technique of measuring pattern dimensions at a desired position on a cross-sectional shape of the pattern. Patent Document 1 describes, for example, “a dimension measuring method and an apparatus thereof configured to: acquire a secondary-electron image of a sample by using a scanning electron microscope; create an image profile of a pattern, of which dimensions are to be measured in the acquired secondary-electron image, by using the secondary-electron image; search a model profile that matches the most with the above-described created image profile from a plurality of model profiles, which are stored in advance, are obtained from secondary-electron images of a plurality of patterns having known cross-sectional shapes and dimensions and having mutually different shapes, and are respectively corresponding to the plurality of patterns; and obtain dimensions of the pattern by using the information of the model profile obtained by searching”.
Patent Document 2 describes, for example, “as a scanning charged-particle beam apparatus that irradiates an insulator or a semiconductor sample with a primary charged-particle beam and detects a signal obtained from the sample, a scanning charged-particle beam apparatus capable of significantly reducing an electrification phenomenon of the sample is achieved”.
Patent Document 3 describes, for example, correction of a transmission line from a blanking control circuit to blanking control electrodes in relation to blanking control (described later).